How can I add soft body physics to multiple objects at once?
This will work for any type of physics.
Select all the objects then hold SHIFT and select the object you want to copy from,
this will make it the active object.
Now simply press CTRL + L and select modifiers,
Since all Physics Properties are modifiers this will copy the same physics setting to all the objects
NOTE: This will also copy any other modifiers present on the base object.